Moose Disease Presented By: Andrew & Simla

Moose Disease Presented By: Andrew & Simla

Location • Moose observed at Elk Island National Park 40 km east of Edmonton in central Alberta, Canada Population estimated at 339 Bulls (adult males), Cows (adult females), & Calves (male/female <1 yr old)

Study • Moose were observed from a vehicle using binoculars • Grooming behavior was observed • Oral grooming (tongue, teeth, or both) • Scratch grooming (hoof of hind leg) • Head-rub grooming (side of head) • Relative hair loss determined • Shape of the “bell” • Tuft of hair hanging under the lower jaw

Observations • October through April (Winter) • Proportion of hair loss & rate of grooming increased • Highest in March and April • Premature loss of winter coat • Increased grooming: • Feeding activity • Hair loss

Observations

Hypotheses?

Results • Hair loss and increased grooming due to winter ticks (Dermacentor albipictus)

Winter Ticks • Egg • Laid in spring time in ground litter • 3-6 weeks they hatch • Larva • Bunch together & wait for cold weather (autumn) • Climb nearest plant and wait for moose • A moose brushes against plant • Tick “quests” (waves its forelegs and attempts to latch onto the moose) • Crawl down hair to base & bury mouth into flesh • After feeding they molt into nymphs

Winter Ticks • Nymph • Feed and molt into adult male and female ticks • Takes several weeks • Adults • Mate • Female takes her last feed • Takes several days • Engorges to several times her size • Female falls off in early spring and lay eggs

Winter ticks on moose • Moose will aggressively groom themselves to attempt to dislodge the ticks • Results in hair loss • Hair loss excessive in late winter when adult ticks are feeding • Body heat loss and blood loss • Spend more time grooming • Increased energy expenditure • Less time foraging for food • Reduced mass gain and depletion of reserves

Effect on Ungulate Populations • Three main hosts: • Moose (Alces alces), • Elk (Cervus elaphus), • White-tailed deer (Odocoileus virginianus). • Decrease in populations due to: • Hair loss and damage (hypothermia), • Chronic weight loss (reduced growth and fat stores), • Anemia.

Numbers on Decreased Populations • Isle Royale moose population (210 square mile): • Year 2000: 1100 • Year 2007: <400 • Alberta, Canada proportion of moose (January 1 to April 30, 1999): • 92% had evidence of hair loss • 28% of them were dead. • Alberta, Canada proportion of calves: • January 1998: 0.44 • March 1998: 0.26

Ideas about Management or Control? http://wildlife1.usask.ca/wildlife_health_topics/images/tick_stages.jpg

Ideas about Management or Control • Prescribed burning for control (Alberta, Canada): • Reduces numbers of some tick species, • Removes the leaf litter (forested areas), • Does not completely remove duff layer (forested areas). • Success of prescribed burning: • Habitat type being burned, • Weather conditions prior to the burn, • Fuel load in the burn site.

Ideas about Management or Control • A slow, hot fire must be maintained to remove duff and litter layer: • Between snowmelt and leaf out in spring, • Burning of engorged females (survive and lay eggs), reducing numbers of larvae transmission for fall. • A fast, hot fire: • In fall (September and early October) to reduce numbers of larvae, • Might cause a decrease forage amount available to ungulates!

Ideas about Management or Control • Using approved acaricides by dipping, spraying the entire animal with high-pressure sprays or whole animal dusts. • Insecticide-impregnated ear tags offer some protection and control when ticks are infesting mainly the ears. • Long-term pasture rest and rotation. • Hire a guinea fowl !

References • Drew, Mark; W. M. Samuel; G. M. Lukiwski; J. N. Willman. 1985. “An Evaluation of Burning for Control of Winter Ticks, Dermacentor albipictus, in Central Alberta.” Journal of Wildlife Diseases. 21(3): 313-315. • Mooring, Michael & Samuel, W. 1999. “Premature loss of winter hair in free-ranging moose (Alces alces) infested with winter ticks (Dermacentor albipictus) is correlated with grooming rate.” Canadian Journal of Zoology. 77: 148-156. • Musante, Anthony; Pekins, Peter; Scarpitti, David. 2007. “Metabolic impacts of winter tick infestations on calf moose.” Alces. http://www.sciencedaily.com/releases/2007/08/070817210729.htm http://www.drovers.com/directories.asp?pgID=714&ed_id=2058 http://www.pested.msu.edu/Resources/bulletins/pdf/2601/LPNE2601chap3.pdf http://wbztv.com/health/guinea.hens.guinea.2.748337.html

Moose Disease Presented By: Andrew & Simla